Screwless means for attaching conductors to electrical devices



Feb. 24, 1959 H. HUBBELL. 2,875,424 scEEwLEss MEANS EOE ATTACHING coNDucToRs To ELECTRIC DEVICES Filed May 1955 vEN'roR 7 /0 /5 ATTORNEYS.

States r SCREWLESS MEANS FOR `ATTA'Cl-IING CON- DUCTORS TO ELECTRICAL DEVICES Harvey Hubbell, :Long Hill, Conn., assignor to Harvey Hubbell, Incorporated, Bridgeport, Conn., a corporation of lConnech'cut Application May 13, 1953, Serial No. 354,833 8 Claims. (Cl. 339-164) i conductors, such as lead wire conductors, to the contacts in electrical devices without the use of the screws.

Another object is to provide such a securing means for the conductor wires which become effective to not only grip and hold the wires but also form an effective elec trical contact, by a mere insertion of the end of the conductor wires into the securing means.

Anotherobject is to provide such a construction in which a flattened screw driver bit or similar tool may be inserted in the connecting means, and by a simple turning movement release the grip on the conductor wire so that it may be removed from and disconnected from the device.

With the foregoing and other objects in view, l have devised the construction illustrated in `the` accompanying drawing forming a part of `this specication. It is, however, to be understood the invention is not limited to the specific details of construction and arrangement shown but may embody various changes and modifications within the scope `of the invention.

In this drawing:

Fig. l is a front elevation oan outlet receptacle em ployed as anexample to illustrate the use and application of the present invention; t

Fig. 2 is a side view thereof;

Fig; 3 is a front view of the rear with the front section removed; i

Figs. 4, 5 and 6 are transverse sections substantially on lines 4 4, 5-5 and 6 6 respectively of Fig. 2;

Fig. 7 is a perspective view of one of the contact elements and connecting means removed from the insulating body;

Fig. 8 is a similar view showing a modification;`

Fig. 9 is a side elevation of a portion of the contact member showing a modified arrangement, and

Fig.` 10 is a transverse section thereof, showing how a conductor wire may be secured thereby. r This improved screwless means for `attaching a conusual binding section of the body ductor wire is shown in connection with an electrical outlet receptacle of the type adapted for mounting in` a Wall outlet box to which the conductor Wires of a house wiring system may be led and connected to the receptacle,

but it will be understood this particular device is used merely by way of example to show the invention, and that this improved connecting means may be used for connecting the lead wires to the contacts of other electrical devices, such, for example, as switches and the like.

The electrical device shown comprising `the electrical outlet receptacle comprises a body member of suitable molded insulating material including the two separable sections 1 and 2 connected by suitable means such as `a screw 3, the body section 1 being provided with cornpartments 4 facing forwardly and in alignment with eny, 2,875,424 lPatented Feb. 24, MB`

trance openings or slots 5 in the front section 2 leading to these compartments for entrance of the contact blades of the standard plug-in connector cap for engagement with receptacle contacts within thereceptacle. This is shown as a duplex receptacle comprising two pairs of these entrance slots, thus permitting the plugging in of two plug-in" caps into this receptacle at the same time. Stationary receptacle contacts of any suitable type are mounted in thecompartments 4 at the inner side of the entrance slots 5, those shown comprising substantially iiat spring metal members 6, one for each of the compartments 4, and are located to the rear of the slots 5 so as to engage the contact blades inserted through these slots. In the duplex receptacle shown there are two pairs of these contacts, and corresponding contacts of each pair are connected by a connecting conductor bar 7. In the ,construction shown this connecting bar-is a strip of resilient conductor metal of thin sheet metal (the thick ness being greatly exaggerated on the drawing) bent at its opposite ends upon itself as shown at 8 to. provide the receptacle contacts 6, and the upper ends may be bent laterally somewhat as shown at 9 to guide the contact blades as they are inserted through the slots 5 to engage one side of the contacts 6. There are two of these connected contact elements in each receptacle, and the open side of the body section 1 is provided with a longitudinal groove 10 in which the lower edge of the bar orstrip 7 is seated, and the upper4 section 2 of the body is provided with corresponding grooves 11 in which the opposite edges of the strips 7 are seated.. Thus when these receptacle contacts and their connecting strips are mounted-in the body they are seated iirst in the grooves 10 in the lower sectionjl, and then when the upper section 2 is placed on the lower section the top edges of the bar 7 are seated in the grooves 11 of the upper section, and then when the two sections are secured together `the two opposite edges of the connecting'bar 7 are rigidly mounted and positioned as indicated in Figs. 5 and 6.` The two sections 1 and 2 of the body are secured together by a screw 3. A mounting yoke 12 comprising a suitably shaped strip of metal is seated ina longitudinal recess 13 in the section 2 of the body and is provided at its opposite ends with the usual mounting ears 14 for mounting it in the usual wall outlet box (not shown) in the house wiring system. At the lower side of the body is an insulating plate 15 of compressed insulating material and the screw is passed through this plate andthreaded into the yoke 12 to thus secure the two body sections together.

For securing the conductor wires to the contacts 6 and the connecting conductor bar or strip 7, this strip is provided with a'narrow longitudinal slot 16, and this may extend any given length desired, and in the device shown `terminates in enlargements 17 at the opposite ends ofthe slot. The side walls of the ,slot between these enlargements are inclined or bent laterally from the plane of the strip 7 in the same direction, and therefore these walls 16a at opposite sides of the slot are inclined backwardly and outwardly in opposite directions from the edges of the slot, and these inclined walls are located on the inner side of the strip opposite the outer walls of the body, so that these walls may yield inwardly under their resilient or spring action to permit the insertion of the bared ends of a conductor Wire into the slot between these edges to be gripped by these edges. The width `of the slot is made such that it is normally somewhat less than the diameter of the wire to be inserted in the slot so that as the wire is inserted it will spread the sides of the slot or force them laterally and outwardly. In other words, the inclined side `walls at opposite sides of` the slot will yieldlaterally and` outwardly as the wire is inserted, and the resilient action of the metal of the strip 7 will cause be seen that as the walls f the opposite sides of the slots are inclined inwardlyfan outward pull on the wire will tend to cause these inclined 'side walls to straighten or narrow'the slot, andthis will cause the sharp or squared-corner edges of the slot to firmly grip the opposite sides of the wire with suicient pull to dig somewhat into the wire, and the greater the pull on'the wire' the greater will be the holding or gripping effect. This clamping or gripping elec't forms a firm hold on the wire to prevent its being withdrawn from the strip, but it also provides a very effective electrical Contact between the strip and the wire.

I'n the drawing, wires of ditferentsizes are shown as being attached to the same strip. That is, the wire 18, for example, may be a larger wire, say ft2-gauge, while the other wire 19 may be of smaller diameter, say 14- gauge, and this attaching means will firmly hold and grip either size of wire, the slot, however, normally, when no wire is inserted, being somewhat narrower than the diameter of the smallest wire to be secured thereby. The resilient yieldable side walls, however, will yield sul'liciently to permit insertion of the larger wire. The holding and gripping effect will be the same for both.

For facilitating insertion of the wires to make lthe electrical connection, the opposite side walls of the insulating body are provided with openings 20 and 21 therethrough in alignment with the slot 16 in the conductor strip, and these openings may be provided in the dividing line 22 between the two sections of the body,

the openings being formed half in each section.V The openings 26 are made larger for the larger wires 18 and the openings 21 smaller for the smaller wires 19, and as the openings are in alignment with the slot 16 they provide means for directing the end of the wire into the lSlot so that in making the electrical connection of these conductor wires to the contacts in the receptacle all that is necessary is to insert the ends of the wire through the proper openings 20 or 21 into Ythe slot 16 in the connector. As shown in Fig. 6 of the drawing, the openings 20 and 21 are preferably carried through the insulating material of the body on both sides of connecting bar 7. As shown in Fig. 2, there are two pairs of openings, that is, two of the larger openings 20 for the larger wire and two of the smaller openings 21 for the smaller'wire, in the arrangement shown being spaced on opposite sides of the receptacle. That is, by connecting two wires to .connector 7 not only may the receptacle contacts 6 be connected to the house wiring system, but the connector 7 may be used as a through connection continuing the house circuit through the receptacle. As the opposite edges of the strip orbar Z are seated and held in the grooves or channels 10 and 11 of the body sections 1 and 2, this strip or bar is firmly held against lateral movement. It is therefore held against inward movement as a wire is inserted and spreads the opposite sides of the slot inwardly and laterally. These channels also hold the strip or bar 7 from outward movement by an outward pull on a wire while gripped and held in the slot 16.

Referring to Fig. 2, there is shown between the openings an enlarged elongated opening 23 also in align ment with the slot 16, and this opening is large enough to permit insertion of the flattened bit end of a screw driver or similar tool, indicated in broken lines 24, into the slot 16, and then by turning this bit it will spread apart, or cause the side edges of the slot 16 to yield or spread outwardly to release the conductor wires 18 or 19 and permit them to be withdrawn from the receptacle. It will be clear that this is a very simple operation to merely insert the bit of the screw driver and turn it to release the wires, andV then after the bit has been removed vthe same or other wires may be easily and quickly connected to the device by merely inserting their free ends the free edges of y u the slot to grip the opposite sides of the wire. It will into the openings 20 or 21 and into the slots 16 in the connector bar.

In the modified arrangement of Fig. 8, the slot corresponding to the slot 16,' instead of being a straight slot of substantially uniform width, as shown in Fig. 7, is stepped or widened at the central portion, as indicated at 25, leaving narrower portions 26 at the opposite ends to receive the ends of the wiresto be connected to the device. In this way somewhat greater exibilit'y is secured, as only the shortened portions 26a at the OPPOSite sides of the portion 26 of the slot need yield as the wire is inserted. In this case the screw driver bit or similar tool for releasing the wires would be inserted in the wider portion 25 of the slot, the walls 25a at the opposite edges of this widened portion being inclined in opposite directions away from the sides of the slot to effect the operation the same as in the first form.

In the modification shown in Figs. 9 and y10 theconnecting bar or strip 7 is the same as in the other forms and connects the two stationary contacts 6 (not shown), but in this case the longitudinal'slot 27 for receiving and securing the conductor wires is the same as in the form of Fig. 7 and the walls are inclined in opposite directions from the opposite edges of this slot the same as in the iirst form, as shown at 28, to receive the conductor wire 13 or 19, except that in this case either one or both edges of the slot are provided with a series of small teeth 30 which may be saw-like teeth to give a more piercingv grip to the wire, and theyalso would prevent the wire sliding longitudinally in the slot. Otherwise the construction, operation and effect is the same as in the other forms.

A holding or gripping effect on the wire could be secured by inclining the side wall on only one side of the slot, leaving the other straight, but this is not as eiective or satisfactory as inclining both sides as shown.

It will be clear'from the above that this means of securing the lead wires to the contacts in the device is a very simple one which eliminates the use of the usual binding screws, which involves the making of the` screw, tapping the hole in the supporting base and assembling of the screw, all of which operations are eliminated in this device, and it further simplifies the` connection of the lead wire to the contact as it eliminates the necessity of winding the wire about the stem of a screw and the setting up of the screw. ln other words, all that is necessary in making thc connection is to insert the end of thc wire in a slot formed between the oppositely inclined walls, and the connection is completed. Furthermore, the greater the pull outwardly on the lead wire the greater is the gripping and holding eliect, and there is nothing to loosen up or inadvertently release the lead wires as often happens where binding screws are used asV the connecting means.

Having thus set forth the nature of my invention, I claim: l

l. In a device of the character described, an: insulating body member having a-side wall, an electrical contact in said member, means for connecting a conductor vwire to said contact comprising a substantially dat elongated strip of resilient conductor metal connected to the Contact and provided with a longitudinal narrow slot, the walls of the strip inclined and extending laterally from the edges of the slot and yieldable to permit insertion of the' bared end of a conductor wire through the slot between said edges to be gripped thereby, the side wall of the insulated body provided with an opening in alignment with the slot to direct the bared end of the wire into the slot, and said body provided with another opening to one side of the first opening and in alignment with the slot to permit insertion of a flattened screw driver bit and the like into the slot andby a turning action to separate the edges of the slot and release the wire.

2. In a device of the character described, an insulating s body member provided with a side wall, a pair of spaced electrical contacts in said member, means for connecting a conductor wire to the contacts comprising a substantial* ly flat elongated strip of resilient electrical conductor metal extending between and connected to the contacts, said strip provided with a narrow elongated longitudinal slot, the walls of the strip inclined and extendingly laterally from the edges of the slot and yieldable to permit insertion of the bared end of the conductor wire through the slot betweensaid edges to be gripped thereby, said body provided with longitudinally spaced openings in its side wall in alignment with the slot to direct the bared ends of conductor wires into the slot, and said wall of the body also provided with an opening between the iirst openings in alignment with the slot for insertion of a attened screw driver bit and the like into the slot and by a turning movement to separate the opposite edges of the slot and release the wires.

3. In a device of the character described, an insulating body member having a side wall, an electrical contact in said member, means for connecting a conductor Wire to said contact comprising a substantially ilat elongated strip of resilient conductor metal connected to the contact and provided with a longitudinal narrow slot, the Walls of the strip on at least one side of the slot inclined and extending laterally from the adjacent edge of the slot and yieldable laterally to permit insertion of the barred end of a conductor wire through the slot `between its edges to be gripped thereby, said body being provided with longitudinal oppositely facing spaced grooves in which the opposite outer edges of the strip are seated and held against lateral movement, and the side wall of the insulating body provided with an opening in alignment with the slot to direct the bared end of the wire into the slot.

4. In a device of the character described, an electrical contact, and means for connecting a conductor wire to said contact comprising a substantiallyat elongated strip of resilient conductor metal connected to the contact and provided with a narrow longitudinal slot having edges at least one of which comprises a series of teeth, the walls of the strip inclined and extending laterally from the edges of the slot and yieldable to permit insertion of the end of a conductor wire through the slot between said edges to be gripped thereby, said teeth providing means to increase the grip on the wire and hold it against sliding longitudinally in the slot.

5. In a device of the character described, an insulating body member comprising two superimposed sections pro vided with longitudinal aligned grooves in their opposed faces, an electrical contact in said member, means for connecting a conductor Wire to said contact comprising a substantially iiat elongated strip of resilient conductor metal connected to the contact and provided with a longitudinal narrow slot, the walls of the strip inclined and extending laterally from the edges of the slot and yieldable to permit insertion of the free end of a conductor wire through the slot between said edges to be gripped thereby, and the outer side edges of the strip seated in said grooves to beheld thereby against lateral movement as the wire is inserted in the slot and also by a pull on the wire.

6. Electric wiring apparatus in combination, an insulating housing, an electrical contact in said housing and means for connecting a conductor to said contact compris ing an elongated iiat strip of resilient metal connected to the contact and provided with a longitudinal central slit, the metal of the strip adjacent the slit forming converging wings to guide and receive a bared conductor between the free edges of the slit to grip the same and resist withdrawal, means forming part of said housing engaging the outer edges of said strip wings to prevent spreading there of on attempted conductor withdrawal, .and a conductor entrance hole in said housing aligned with said slit.

7. Electric wiring apparatus in combination, a rigid insulating housing having a longitudinally channeled body and a cover, an electric contact wholly submerged in said channel, means for connecting a conductor to said contact comprising an elongated strip of resilient metal endconnected to said contact, lying along the channel bottom and longitudinally centrally slit, the slit edges forming borders for converging wings extending laterally from a wall of said channel and yieldable to accept the bared end of a conductor through the slit for gripping by said borders, a wall of said body having a wire receiving hole therethrough in alignment with the slit to direct a conductor thereto, and a second larger hole in the same align ment but spaced from the first to receive a nail to spread the wings and release a gripped Wire from the slit.

8. The apparatus as defined in claim 7 in which the outer edges of said strip are closely engaged by the channel -walls adjacent said wings to prevent Spreading of the latter on the application of withdrawal tension on the conductor.

References Cited in the le of this patent 4UNITED STATES PATENTS 1,625,485 Maurer Apr. 19, 1927 1,678,745 Schellenger July 31, 1928 1,839,522 Alden lian. 5, 1932 1,950,826 Smart Mar. 13, 1934 2,058,745 Weber Oct. 27, 1936 2,114,523 Cleveland Apr. 19, 1938 2,206,799 Barton July 2, 1940 2,214,065 Pennock Sept. 10, 1940 2,259,740 Del Camp Oct. 21, 1941 2,519,121 Del Camp Aug. 15, 1950 2,551,844 Kueck May 8, 1951 2,591,009 Riche Apr. 1, 1952 2,705,785 Benander Apr. 5, 1955 FOREIGN PATENTS 659,316 Great Britain Oct. 24, 1951 

